Along the wall Bx, cos nθ = 1, sin nθ = 0,

b > u > 0

(27)

ch nΩ = ch log ( Q) n= √ b − a′ a − u,
q a − a′ b − u

(28)

sh nΩ = sh log ( Q) n= √ a − b u − a′.
q a − a′ b − u

(29)

At x where φ = ∞, u = 0, and q = q0,

( Q) n= √ b − a′ a+ √ a − b −a′.
q0 a − a′ ba − a′ q

(30)